The Infineon CY7C027-20AC is a 512Kbit asynchronous dual-port SRAM organized as 32K words by 16 bits, in a 100-TQFP surface-mount package. It provides two independent ports with separate address, data, and control lines, allowing two bus masters (e.g., a DSP and a microcontroller, or two processors) to access the same memory array without external arbitration logic. The 20 ns access time on each port supports back-to-back read/write cycles at bus speeds up to 50 MHz, and the 5V supply rail is common in legacy telecom and industrial control backplanes.
20 ns access — timing margin for shared buses
In a dual-port design, both ports run at this speed, so the bus-turnaround overhead is symmetric. For a system clocked at 40 MHz (25 ns period), the 20 ns access leaves 5 ns of margin for PCB trace delay and setup time on the host — enough for a single backplane slot but tight for a multi-drop bus. If your controller runs at 50 MHz or faster, the 20 ns window becomes the critical path; verify hold times against the port's data-sheet timing parameters.
Infineon (formerly Cypress) no longer manufactures this part; no factory last-time-buy window remains open. Sourcing is limited to independent-distribution surplus and broker inventory. No official successor part is recorded; the CY7C027 family shares a common footprint, so a faster speed grade (e.g., CY7C027-25AC) may be a drop-in candidate if the timing budget allows.